[0001] The invention relates to a process for cross-linking a polymer or a resin with the
help of a peroxide, in the presence of a co-agent.
[0002] Polymers and resins that are cross-linked are for instance elastomers and thermosetting
resins. Before the cross-linking, these polymers and resins are liquid at room temperature
or at an elevated temperature, so that they can be processed into moulded parts, for
instance by casting, compression moulding, injection moulding, extrusion, When moulded,
the polymer or the resin is cross-linked, whereby the polymer or the resin obtains
its final properties as desired in view of the application. Thus, many cross-linked
thermosetting resins exhibit a high stiffness, also at very high temperatures. Cross-linked
elastomers behave rubber-like, as manifested for instance in a relatively low stiffness
and a high, reversible elongation.
[0003] Depending on the type of polymer or resin it is possible to effect the cross-linking
by means of a free-radical reaction, mostly with the help of peroxide. In order to
enhance the efficiency of such a reaction it is often carried out in the presence
of a co-agent. Due to the presence of a co-agent a network having a higher cross-link
density is obtained, with the same amount of peroxide supplied. It is also possible
to use a smaller amount of peroxide and yet obtain a comparable cross-link density.
A co-agent is a compound which in the cross-linking process is integrated into the
polymer network. A co-agent mostly has two or more carbon-carbon double bonds. Examples
of the most commonly applied co-agents are triallyl cyanurate (TAC), polybutadiene,
trimethylolpropane-tris-methacrylate (TRIM) and metaphenylene bis(maleimide) (BMI).
Drawbacks of the known co-agents are for instance that they still lack efficiency
or that, while being efficient, they already react at a too low temperature. An example
of a co-agent which often exhibits a less than efficient cross-linking reaction is
TAC. The use of BMI as a co-agent is known from W. Hofman's 'Rubber Technology Handbook',
(Hanser, 1996), page 107, lines 8-9. When bismaleimides are used as co-agent, the
cross-linking reaction is mostly efficient, but the cross-linking reaction rate is
too high at low temperatures. As a result, premature cross-linking will occur during
the processing into the moulded part, and because of the accompanying polymer viscosity
increase, processing of the polymer into the moulded part is not possible or is defective.
[0004] The aim of the invention is to provide a process for cross-linking a polymer or a
resin with the help of a peroxide, in the presence of a co-agent, whereby a highly
efficient cross-linking reaction is obtained while nevertheless no or hardly any premature
cross-linking occurs during the processing of the polymer or the resin into a moulded
part.
[0005] Surprisingly, such a process is obtained due to a compound according to formula 1:

being used as co-agent,
where n is higher than or equal to 2,
R1 is an aliphatic or aromatic group and the R2 and R3 groups, independently of each other, are a hydrogen atom, an aliphatic or an aromatic
group.
[0006] With the process according to the invention a highly efficient cross-linking reaction
is obtained, while nevertheless no or hardly any premature cross-linking occurs during
the processing of the polymer into a moulded part. A further advantage is the good
miscibility of the compounds according to formula 1 with many polymers.
[0007] Another further advantage is that the compounds according to formula 1 can be prepared
in a simple manner. Yet another further advantage is that the polarity of the polymer
obtained after cross-linking can be increased with compounds according to formula
1. This enables for instance the oil resistance of non-polar elastomers to be improved.
[0008] From US-3,502,542 a process is known for bonding metal to a rubbery elastomer, comprising
the steps of preparing a mixture comprising an elastomer and an acidic compound and
curing said elastomer by introducing free radicals while contacting said metal and
said elastomer. As acidic compounds in a long list for example Carboxylic acids comprising
more than one N-maleimido or N-maleamic acid radicals are mentioned. The group according
to formula 1 is not disclosed. However N,N'-(1,3-phenylene)di-maleamic acid is mentioned.
US-3,502,542 is silent about efficiency of the cross-linking reaction. A method of
binding an elastomer to a metal substrate by using N,N'-(1,3-phenylene)di-maleamic
acid is therefore excluded from protection.
[0009] From JP-A-9012542 it is known to crosslink a mixture comprising a bismaleiimide and
a bismaleiimide acid ester. However nothing is said about the crosslink efficiency.
A process for crosslinking a mixture comprising a bismaleiimide and a bismaleiimide
acid ester are therefore excluded from protection.
[0010] From US-4,278,586 a method of improving the adhesion between a polymer composition
and a fiber is disclosed, by incorporating a bismaleiimide acid in the polymer composition.
No peroxide cross-linking however is applied.
[0011] From EP-A-619343 a method is known for coating metal pipes with a polymer composition.
To prepare the composition a modified polypropylene is added to a crosslinked polyolefin.
The polypropylene is modified by for example an isopherone bismaleamic acid. However
the bismaleic acid is grafted onto the polypropylene and no cross-linking reaction
takes place in the presence of the bismaleic acid. If R
1 of the compound according to formula 1 is an aromatic group, then R
1 is preferably a phenyl group. If R
1 is an aliphatic group, then R
1 preferably contains 1-12 C atoms. Still more preferably, R
1 is an aliphatic group with two or six carbon atoms. Most preferably, R
1 is an aliphatic group with six carbon atoms. The value of n preferably is 2-4. More
preferably, the value of n is 2. R
2 and R
3 are preferably each a hydrogen atom.
[0012] The double carbon-carbon bond shown in formula 1 can be either in the cis or in the
trans configuration. Preferably, the double carbon-carbon bond is in the cis configuration.
Examples of suitable compounds according to formula 1 are phenylene bis(maleamide
acid) (FBMA) and hexamethylene bis(maleamide acid) (HMBMA). Preferably, hexamethylene
bis(maleamide acid) is used.
[0013] The compounds according to formula 1 can be prepared for instance by reacting a compound
having at least 2 amine groups with an equimolar amount of α-β unsaturated dicarboxylic
acid, anhydride, ester or semi-ester.
[0014] The reaction can be carried out for instance by dissolving the compound with the
amine groups and combining the carboxylic acid, the anhydride, the ester or the semi-ester
with stirring, keeping the temperature between 0 and 30°C. Suitable solvents are for
instance tetrahydrofuran and methyl-tert-butyl ether (MTBE).
[0015] In principle all polymers and resins that can be cross-linked with the help of a
peroxide can be used in the process according to the invention. These are often polymers
or resins without double bonds in the main chain. However, it is also possible to
use polymers or resins with double bonds in the main chain.
[0016] By cross-linking the polymer or resin is understood that at least part of the polymer
or resin formes a three-dimensional polymer network. This means that the part of the
polymer or resin forming the three-dimensional network, also mentioned gel fraction,
cannot any more be dissolved in a suitable solvent for the polymer or resin. The sol
fraction is the part of the polymer or resin still being dissolved in the solvent.
Together the gel fraction and the sol fraction form 100 % of the polymer or resin.
[0017] Preferably the gel fraction is at least 50 %, more preferably 75 %, still more preferably
at least 95 %, most preferably at least 99 %.
[0018] Examples of thermosetting resins which are suitable for use in the process according
to the invention are unsaturated polyester resins, alkyd resins, acrylate resins.
[0019] The process according to the invention gives good results when applied for the cross-linking
of elastomers. Examples of elastomers which are very suitable to be used in the process
according to the invention are chlorosulphonated polyethene (CSM), acrylate rubbers
(ACM), chlorinated polyethene (CM), hydrogenated nitrilbutadiene rubber (H-NBR), silicone
rubber (QM), fluororubber (FKM), polyethene vinylacetate (EVA), elastomers obtained
by the polymerization of ethene and an alpha olefin (for instance EPM) and elastomers
obtained by the polymerisation of ethers, an alpha olefin and a non-conjugated polyene
(for instance EPDM).
[0020] The process according to the invention gives very good results when using elastomers
obtained by the polymerization of ethene and an α-olefin (EPM). As α-olefin an α-olefin
with 3-10 carbon atoms can for instance be used; examples are propene, butene, hexene,
octene etc. Preferably, propene is used.
[0021] The process according to the invention also gives very good results when using elastomers
obtained by polymerization of ethene, an α-olefin and a non-conjugated polyene (EPDM).
[0022] As α-olefin is used for instance an α-olefin with 3-10 carbon atoms; examples are
propene, butene, hexene, octene etc. Preferably, propene is used.
[0023] The ethene to α-olefin weight ratio is preferably between 90/10 and 20/80. Preferably,
the ethene to α-olefin weight ratio is between 70/30 and 40/60.
[0024] Examples of non-conjugated polyenes to be applied in the EPDM are 5-ethylidene-2-norbomene,
5-vinyl-2-norbomene, dicyclopentadiene or 1,4 hexadiene or mixtures thereof. The preparation
of EPDM is known to the person skilled in the art. EPDM can for instance be prepared
by polymerization with the help of a Ziegler-Natta catalyst or a metallocene catalyst.
[0025] The process according to the invention also gives very good results when chlorosulphonated
polyethene (CSM) is used. CSM can for instance be prepared by means of UV irradiation
of polyethene in an inert chlorinated solvent at 70 - 75°C in the presence of gaseous
chlorine and sulphur dioxide. The preparation of CSM is known to the person skilled
in the art.
[0026] A yet further improved process according to the invention is obtained if the cross-linking
of the CSM is carried out in the presence of a peroxide, a co-agent and an amine accelerator.
The polymer composition contains for instance 7 * 10
-4 - 2.2 * 10
-1 mol of the amine accelerator per kilogram of CSM. Preferably, the polymer composition
contains 3.5 * 10
-2 - 1.5 * 10
-1 mol of the amine accelerator per kilogram of CSM.
Preferably, tertiary amines are used as amine accelerator. More preferably, use is
made of hexamethylene tetramine (HMTA).
[0027] Prior to carrying out the process according to the invention, a composition is mostly
prepared which contains the polymer or the resin, the peroxide and the co-agent, by
mixing the polymer or the resin, the peroxide and the co-agent at a temperature below
the temperature at which the polymer or the resin is cross-linked. The peroxide and
the co-agent can be mixed simultaneously with the polymer or the resin, but it is
also possible to mix the co-agent and the peroxide successively with the polymer or
the resin. It may be of advantage for instance, to mix the peroxide with the polymer
or the resin, which is previously mixed with the co-agent, shortly prior to the processing
the composition into a moulded part. In this way the polymer or the resin is prevented
from cross-linking already during storage subsequent to the mixing and prior to processing
of the composition into the moulded part.
[0028] Examples of suitable peroxides are di-tert-butylperoxide, bis(tert-butylperoxyisopropyl)benzene
(Perkadox™ 14/40 MB, Akzo Chemie), dicumylperoxide, butyl 4,4-bis(tert-butylperoxy)valerate,
2,5- bis(tert-butylperoxy)-2,5-methylhexane, 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyn,
tert-butyl 3-isopropenylcumylperoxide.
[0029] The composition containing the polymer or the resin contains for instance 2.9 * 10
-3 - 3 * 10
-1 mol peroxide per kilogram of polymer or resin. Preferably, the composition contains
1.1 * 10
-2 -1.5 * 10
-1 mol peroxide per kilogram of polymer or resin. More preferably, the composition contains
1.4 *10
-2 - 8.9 *10
-2 mol peroxide per kilogram of polymer or esin. At this relatively low peroxide concentration
the invention is highly effective.
[0030] The composition contains for instance 3.1 * 10
-2 ― 4.8* 10
-1 mol co-agent per kilogram of polymer or resin. Preferably, the composition contains
6.2 * 10
-2 - 3.2 * 10
-1 mol co-agent per kilogram of polymer or resin. More preferably, the polymer composition
contains 6.2 * 10
-2 ― 1.6 * 10
-1 mol co-agent per kilogram of polymer or resin.
[0031] The processing of the composition containing the polymer or the resin, the peroxide
and the co-agent into a moulded part usually takes place at a temperature higher than
room temperature. Raising the temperature causes the viscosity of the composition
to decline and as a result the moulding is made easier. That is why it is important
to carry out the moulding at a relatively high temperature. At the same time, however,
it is also important that the cross-linking reaction does not take place, or only
to a minor extent, prior to the moulding. After the moulding the temperature of the
composition is usually increased further, so that the peroxide decomposes and the
cross-linking reaction takes place. In this relation it is important that the cross-linking
reaction takes place efficiently. So during the moulding the reaction should not occur
or only to a minor extent, while after the moulding the reaction should take place
efficiently. It has been found that due to the use of the co-agent according to formula
1 in the process according to the invention an efficient cross-linking reaction is
obtained while nevertheless no or hardly any premature cross-linking occurs during
the processing of the polymer or resin into a moulded part.
[0032] The process according to the invention will now be illustrated by means of the following
[0033] A maleic anhydride solution was prepared by dissolving 15.0 grams (0.153 mol) of
maleic anhydride in 250 ml of tetrahydrofuran with stirring at room temperature. In
5 minutes a solution of 8.27 grams (0.076 mol) of metaphenylene diamine in 250 ml
of tetrahydrofuran was added dropwise to the maleic anhydride solution. A yellow suspension
was obtained. Next the whole was stirred for 10 minutes, after which the yellow suspension
was filtered and washed with 50 ml of tetrahydrofuran. The residue was a yellow solid
substance in powder form, 23.1 grams (0.076 mol). Part of this yellow solid substance
was dissolved in dimethyl sulphoxide (DMSO) and it was then identified as FBMA by
means of 1 H-NMR measurements.
[0034] The preparation of the test material took place in an internal mixer (Brabender Plasticorder,
50 cc). The composition data of the test material are presented in Tables 1 and 4.
Keltan™ 720 (EPDM, DSM) was first introduced into the kneader, at a temperature of
75°C, followed by the other ingredients, except for the peroxide and the co-agent.
The whole was kneaded for 1 minute at 40 rpm and 75°C. Then the peroxide and the co-agent
were added to the composition, which subsequently was kneaded for 4 minutes under
the same circumstances. Then the test material was pressed in 2 minutes at 60°C to
2 mm thick sheets in a Fonteijne press, after which the measurements were effected.
[0035] The test material obtained was tested according to IS06502 and ISO667. The ISO6502
test method was used to determine the cross-linking efficiency under the curing conditions
for the material. The measurements were performed with a Monsanto™ rheometer MDR 200
E. The measurement took place at 180°C in 1200 seconds (20 minutes). A maximum and
a minimum torque (N.m) were determined, as well the time at which 90% of the maximum
torque had been reached (t90). The maximum torque is a measure of the degree of cross-linking
of the material. The higher the maximum torque, the higher the degree of cross-linking.
The t90 value is a measure of the rate of cross-linking. The lower t90, the higher
the rate at which the cross-linking takes place.
[0036] The test method according to ISO667 was used as a method of measurement to determine
the degree of cross-linking of the material under moulding conditions.
[0037] The measurements were carried out with the Monsanto™ Mooney MV 2000E. The measurements
took place at 125°C in 3600 seconds (60 minutes). The development of the viscosity
shows whether premature cross-linking of the material occurs. The viscosity is expressed
in Mooney units (MU). An increase in viscosity indicates the occurrence of cross-linking.
The initial viscosity and the minimum viscosity were measured.
[0038] In addition, the points in time were determined at which the viscosity had increased
by 2, 5 and 35 Mooney units, respectively, relative to the minimum viscosity (t2,
t5 and t35, respectively). The measured t2, t5 and t35 provide an indication of the
cross-linking reaction rate. The faster these points in time follow each other, the
faster the cross-linking takes place.
Example I and comparative experiments A and B
Comparison of hexamethylene bis(maleamide acid) (HMBMA) and triallyl cyanurate (TAC)
[0039]
Table 1. Composition of test material
| Ingredient |
From |
I |
A |
B |
| Keltan™ 720 (EPDM) |
DSM |
100 |
100 |
100 |
| ZnO active |
Bayer AG |
5 |
5 |
5 |
| Stearic acid |
HCHM SA/18, Simel S.p.A |
0.5 |
0.5 |
0.5 |
| N-550 carbon black |
Sterling SO, Cabot B.V. |
70 |
70 |
70 |
| Mikrosöhl™-M40 whiting |
Ver. Kreidewerke Dammann |
40 |
40 |
40 |
| Tudalen™ B 8014, paraffinic oil |
Klaus Dahleke KG |
70 |
70 |
70 |
| Perkadox™ 14/40 MB |
Akzo Chemie B.V. |
2 |
2 |
2 |
| HMBMA |
|
5 |
|
|
| TAC-70 |
Degussa AG |
|
|
5 |
| Total phr |
|
292.5 |
287.5 |
292.5 |
[0040] The composition of the test materials used in example I and in comparative experiments
A and B is shown in table 1. The test material of example I was prepared according
to the process of the invention and contains HMBMA as co-agent. Comparative experiment
A relates to a test material prepared without a co-agent, while for experiment B TAC
was used as co-agent.
Table 2. Results of measurements under curing conditions
| ISO 6502 |
|
I |
A |
B |
| Minimum torque |
N.m |
0.07 |
0.07 |
0.07 |
| Maximum torque |
N.m |
0.52 |
0.29 |
0.35 |
| t90 |
s |
352 |
280 |
400 |
[0041] Comparing in table 2 the results of example I with comparative experiments A (no
co-agent) and B (TAC as co-agent) it is seen that the maximum torque of example I
is higher than in comparative experiments A and B. A higher maximum torque is indicative
of a higher degree of cross-linking of the test material. In addition, the time at
which 90% of the maximum torque has been reached is shorter in example I than in comparative
experiment B, which indicates that the cross-linking reaction rate in example I is
higher. So it can be concluded that the use of HMBMA as co-agent results in a higher
efficiency of the cross-linking reaction than TAC.
Table 3. Results of measurements under moulding conditions
| ISO 667 |
|
I |
A |
B |
| Initial Mooney |
MU |
32.7 |
32.7 |
32.0 |
| Minimum Mooney |
MU |
21.3 |
20.0 |
19.8 |
| t2 |
s |
- |
- |
- |
| t5 |
s |
- |
- |
- |
| t35 |
s |
- |
- |
- |
[0042] From the measurement results in table 3 it appears that in none of the examples cross-linking
occurs in the test period. This indicates that there is no premature cross-linking
under moulding conditions, i.e. when the material is moulded.
Example II and Comparative Experiments A and C
Comparison of hexamethylene bis(maleamide acid) (HMBMA) and trimethylolpropane-tris-acrylate
(TRIM)
[0043]
Table 4. Composition of test material
| Ingredient |
From |
II |
A |
C |
| Keltan™ 720 (EPDM) |
DSM |
100 |
100 |
100 |
| ZnO active |
Bayer AG |
5 |
5 |
5 |
| Stearic acid |
HCHM SA/18, Simel S.p.A |
0.5 |
0.5 |
0.5 |
| N-550 carbon black |
Sterling SO, Cabot B.V. |
70 |
70 |
70 |
| Mikrosöhl™-M40 whiting |
Ver. Kreidewerke Dammann |
40 |
40 |
40 |
| Tudalen™ B 8014, paraffinic oil |
Klaus Dahleke KG |
70 |
70 |
70 |
| Perkadox™ 14/40 MB |
Akzo Chemie B.V. |
2 |
2 |
2 |
| HMBMA |
|
10 |
|
|
| Sartomer™ 350 (TRIM) |
Cray Valley |
|
|
10 |
| Totaal phr |
|
297,5 |
287,5 |
297,5 |
[0044] The composition of the test materials used in example II and in comparative experiments
A and C is shown in table 4. The test material of example I was prepared according
to the process of the invention and contains HMBMA as co-agent. Comparative experiment
A relates to a test material prepared without a co-agent, while for experiment C TRIM
was used as co-agent.
Table 5. Results under curing conditions
| ISO 6502 |
|
II |
A |
C |
| Minimum torque |
N.m |
0.08 |
0.07 |
0.06 |
| Maximum torque |
N.m |
0.58 |
0.29 |
0.58 |
| t90 |
s |
448 |
280 |
368 |
[0045] From table 5 it appears that in example II (HMBMA as co-agent) and comparative experiment
C (TRIM as co-agent) the same maximum torque is reached. This indicates that the two
co-agents give a comparable cross-linking efficiency under curing conditions.
Table 6. Results under moulding conditions
| ISO 667 |
|
II |
A |
C |
| Initial Mooney |
MU |
33.8 |
32.7 |
26.9 |
| Minimum Mooney |
MU |
22.0 |
20.0 |
16.6 |
| t2 |
s |
- |
- |
1292 |
| t5 |
s |
- |
- |
1340 |
| t35 |
s |
- |
- |
1548 |
[0046] From table 6, however, it appears that the test material of comparative experiment
C (TRIM as co-agent) begins to cross-link under the moulding conditions, while in
example II (HMBMA as co-agent), as in comparative experiment A (no co-agent), there
is no cross-linking yet.
Further, in experiment C the relatively small difference in time between the moment
at which the viscosity has increased by 2 units relative to the minimum viscosity
under the moulding conditions and the moment at which the viscosity has increased
by 35 units relative to the minimum viscosity under the moulding conditions indicates
that, once the cross-linking reaction has started, cross-linking takes place rapidly
under the moulding conditions. This indicates that when HMBMA is used as co-agent
in the moulding of the material, there is hardly any cross-linking, in contrast to
the effect of TRIM being used as co-agent. A low degree of cross-linking under the
moulding conditions is desirable.

1. Process for cross-linking a polymer with the help of a peroxide, in the presence of
a co-agent,
characterized in that a co-agent according to formula 1

is used, in which n is higher than or equal to 2, R
1 is an aliphatic or aromatic group and the R
2 and R
3 groups, independently of each other, can be a hydrogen atom, an aliphatic or an aromatic
group, excluding a process for cross-linking a composition comprising a bismaleimide
resin and a bismaleiimide acid ester and excluding a process for binding an elastomer
to a metal substrate by using N,N'-(1,3-phenylene)di-maleamic acid and that the polymer
is obtained by the polymerisation of ethylene and an α-olefin or by the polymerisation
of ethylene, an α-olefin and a non-conjugated di-olëfin.
2. Process for cross-linking a polymer with the help of a peroxide, in the presence of
a co-agent,
characterized in that a co-agent according to formula 1

is used, in which n is higher than or equal to 2; R
1 is an aliphatic or aromatic group and the R
2 and R
3 groups, independently of each other, can be a hydrogen atom, an aliphatic or an aromatic
group; and that the polymer is chlorosul phonated polyethylene.
3. Process according to Claim 1, characterized in that R1 is a phenyl group or a C1 - C12 alkyl group.
4. Process according to any one of Claims 1-2, characterized in that R1 is an aliphatic group with two or six carbon atoms.
5. Process according to any one of Claims 1-3, characterized in that n = 2.
6. Process according to any one of Claims 1-4, characterized in that R2 is a hydrogen atom.
7. Process according to any one of Claims 1-5, characterized in that R3 is a hydrogen atom.
8. Process according to any one of Claims 1-6, characterized in that 1.4 *10-2 - 8.9 *10-2 mol peroxide per kilogram of polymer or resin is used.
1. Verfahren zum Vernetzen eines Polymers mit Hilfe eines Peroxids in Gegenwart eines
Co-Agens',
dadurch gekennzeichnet, dass ein Co-Agens der Formel 1

verwendet wird, bei welcher n größer oder gleich 2 ist, R
1 eine aliphatische oder aromatische Gruppe ist und die Gruppen R
2 und R
3 unabhängig voneinander ein Wasserstoffatom, eine aliphatische oder eine aromatische
Gruppe sein können, ausgenommen ein Verfahren zum Vernetzen einer Zusammensetzung,
welche ein Bismaleimidharz und einen Bismaleimidsäureester umfasst, und ausgenommen
ein Verfahren zum Binden eines Elastomers an ein Metallsubstrat durch Verwenden von
N,N'-(1,3-Phenylen)dimaleaminsäure, und dass das Polymer durch die Polymerisation
von Ethylen und einem α-Olefin oder durch die Polymerisation von Ethylen, einem α-Olefin
und einem nicht-konjugierten Diolefin erhalten wird.
2. Verfahren zum Vernetzen eines Polymers mit Hilfe eines Peroxids in Gegenwart eines
Co-Agens',
dadurch gekennzeichnet, dass ein Co-Agens der Formel 1

verwendet wird, bei welcher n größer oder gleich 2 ist, R
1 eine aliphatische oder aromatische Gruppe ist und die Gruppen R
2 und R
3 unabhängig voneinander ein Wasserstoffatom, eine aliphatische oder eine aromatische
Gruppe sein können, und dass es sich bei dem Polymer um ein chlorsulfoniertes Polyethylen
handelt.
3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass R1 eine Phenylgruppe oder eine C1-C12-A1-kylgruppe ist.
4. Verfahren nach einem der Ansprüche 1 bis 2, dadurch gekennzeichnet, dass R1 eine aliphatische Gruppe mit zwei oder sechs Kohlenstoffatomen ist.
5. Verfahren nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass n = 2.
6. Verfahren nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass R2 ein Wasserstoffatom ist.
7. Verfahren nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass R3 ein Wasserstoffatom ist.
8. Verfahren nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, dass 1,4*10-2 bis 8,9*10-2 Mol Peroxid je Kilogramm Polymer oder Harz verwendet werden.
1. Procédé de réticulation d'un polymère avec l'aide d'un peroxyde, en présence d'un
co-agent,
caractérisé en ce que l'on utilise un co-agent selon la formule 1

dans laquelle n est supérieur ou égal à 2, R
1 est un groupe aliphatique ou aromatique et les groupes R
2 et R
3 peuvent, indépendamment l'un de l'autre, être un atome d'hydrogène, un groupe aliphatique
ou aromatique, à l'exclusion d'un procédé de réticulation d'une composition comprenant
une résine de bismaléiimide et un ester de l'acide bismaléiimide, et à l'exclusion
d'un procédé pour la liaison d'un élastomère à un substrat métallique par utilisation
d'acide N,N'(1,3-phénylène)di-maléamique et que le polymère est obtenu par la polymérisation
d'éthylène et d'une alpha-oléfine ou par la polymérisation d'éthylène, d'une alpha-oléfine
et d'une di-oléfine non conjuguée.
2. Procédé de réticulation d'un polymère avec l'aide d'un peroxyde, en présence d'un
co-agent,
caractérisé en ce qu'on utilise un co-agent selon la formule 1

dans laquelle n est supérieur ou égal à 2, R
1 est un groupe aliphatique ou aromatique et les groupes R
2 et R
3 peuvent, indépendamment l'un de l'autre, être un atome d'hydrogène, un groupe aliphatique
ou aromatique, et que le polymère est du polyéthylène chlorosulfoné.
3. Procédé selon la revendication 1, caractérisé en ce que R1 est un groupe phényle ou un groupe alkyle en C1 à C12.
4. Procédé selon l'une quelconque des revendications 1 ou 2, caractérisé en ce que R1 est un groupe aliphatique avec 2 ou 6 atomes de carbone.
5. Procédé selon l'une quelconque des revendications 1 à 3, caractérisé en ce que n = 2.
6. Procédé selon l'une quelconque des revendications 1 à 4, caractérisé en ce que R2 est un atome d'hydrogène.
7. Procédé selon l'une quelconque des revendications 1 à 5, caractérisé en ce que R3 est un atome d'hydrogène.
8. Procédé selon l'une quelconque des revendications 1 à 6, caractérisé en ce que 1,4* 10-2 - 8,9* 10-2 mole de peroxyde par kilogramme de polymère ou de résine est utilisé.